The invention relates to a vehicle heating system, comprising
(a) a heater having a combustion gas/liquid heat exchanger and operating by burning liquid fuel; PA1 (b) and a liquid/air heat exchanger in fluid flow communication with said combustion gas/liquid heat exchanger to supply heated air to warm the vehicle. PA1 a fan whose blower is connected on the intake side selectively either to. outside air (fresh air) or vehicle inside air (recirculating air); PA1 a heat exchanger fed by the cooling circuit of the motor and disposed within an air and distributor channel on the discharge side of. the blower; PA1 an air guiding and distributing system which is fed with fresh air directly by the fan or with warm air indirectly by the fan with the interposition of the heat exchanger and which opens into the interior of the motor vehicle, PA1 characterized in that, instead of the heat exchanger provided on the vehicle side, there is provided a fuel-operated heater between the fan and the ventilation guiding and distributing system, which is integrated in the heat exchanger and comprises a combustion chamber, with the heat generated by combustion of a fuel air mixture in the combustion chamber being transferred to the water of the cooling circuit of the motor circulating through the heat exchanger around which the air flow produced by the fan circulates directly. The air is thereby heated and conveyed to the vehicle interior.